
December 29, 1999
Meal Planning, Food and Diet
Question from Lawrenceville, Georgia, USA:
I am 44 years old and I was diagnosed Type 1 three years ago. I am having some trouble regulating my diet. I seem to creep up on insulin dosage and then eat to control it. I know this is not right. It sometimes forces me to go extremely low before supper (20-30�mg/dl) sometimes. Do you have some suggestions on how to manage this problem?
Answer:
It’s not possible to give you very specific advice about your challenges regarding matching food and insulin without seeing your food, insulin, and blood glucose records together. But perhaps I can offer some information to help you discuss it with your doctor or educator and figure out what’s best for you.
In attempting to balance food and insulin, you are in effect trying to “play pancreas,” doing what your body would do if you didn’t have diabetes. That is, having small amounts of insulin present between meals and overnight (basal) and then squirting out short bursts of insulin when you eat (bolus). Both aspects of your insulin regimen have to be considered in order for you to be successful in balancing food and mealtime insulin.
The background of insulin — also called the “basal” insulin — is the insulin level between meals and overnight. This level should be set so that the blood glucose level stays stable in your target range when you’re not eating. Most people with type 1 diabetes use either NPH or Ultralente insulin to meet this basal need. Only when the basal insulin is correct can you do a really precise job of matching food and meal insulin. If you quickly become hypoglycemic when you delay a meal, your basal insulin is probably too high at that particular time of day. When you add meal insulin on top of a too high background insulin, you may have hypoglycemia several hours after eating, even if the amount of insulin you took for the food was basically correct.
The choice of meal insulin. If you are trying to match food and insulin, talk to your doctor about using a very rapid meal insulin, (Humalog from Lilly). Regular insulin lasts too long to be an ideal meal time insulin. When you give Regular to cover meals, only part of it is used for food. The rest hangs around for up to eight hours, adding to your risk for hypoglycemia. Humalog peaks quickly and disappears quickly, mimicking much more closely what your body would do if you didn’t have diabetes.
A means to match food and insulin. Since carbohydrate is the chief factor that creates insulin demand in the immediate post-meal period, counting carbohydrates is a very effective tool for matching food to insulin dose. Using blood glucose testing before and after meals, you can figure out the exact relationship for you. Most people with type 1 diabetes require about 1 unit of insulin for each 15 grams of carbohydrate if their background insulin is set correctly. But that is an average — your ratio may be quite different and would need to be set and confirmed on the basis of your own blood sugar experience.
This can be quite a mystery to solve, but I applaud you for making the effort. The sort of diabetes management that you are figuring out is what will give you the greatest flexibility and control.
BB